March: Curiosity fails to find methane, a sign of human life - 20minutes.fr

Curiosity, NASA’s rover on Mars this past thirteen months has undermined the likelihood of the current presence of life on Mars by not detecting methane – a gas that is often a sign of biological activities – in the atmosphere of Mars

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According to measurements taken by the robot, the gas produced 95% by microbes on Earth, if it exists in the Martian environment, can not represent more than 1.3 parts per billion by volume on Mars , barely one-sixth of previously thought, researchers have said in a study published Thursday by the journal Science .

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For 10 years, scientists have made comments plumes of methane in the Martian atmosphere. In March 2003, a group was measured and a cloud of 19,000 tons of methane near the equator of the planet. But these observations were made from Earth or by turning orbiters around Mars.

as methane, the most abundant hydrocarbon in the solar system, may be the signature of biological activity, these ads were fed controversy about the origin of the gas and raised hopes the presence of life on Mars.

“No sign of methane”

But many atmospheric measurements made by a highly sensitive laser spectrometer onboard Curiosity, which landed on Mars in early August 2012, did not lead to the detection of traces of methane – to the surprise of scientists.

“This important result will help to redirect our efforts to examine the possibility of present life on Mars,” said Michael Meyer, chief scientist for Mars exploration at NASA. “This reduces the likelihood of the current existence of Martian microbes producing methane but it is there only one type of bacterial metabolism because we know that on Earth there are many micro-organisms that do not produce methane, “he says.

“It would have been great to find methane, but we are very confident in the accuracy of our measurements,” says Chris Webster, Jet Propulsion Laboratory of NASA: “We have made repeated withdrawals from spring to late summer, but there is no sign of methane. “

Life in loitain past March

Curiosity team will use a method for detecting the presence of methane as one part per billion. Previous observations of plumes of methane on Mars gave concentrations up to 45 parts per billion. Even if this methane was dispersed, there would still be measurable traces insist these scientists.

highest concentration of methane that could be present in the Martian atmosphere without being detected by the laser spectrometer Curiosity could not exceed 10 to 20 tons per year, according to Sushil Atreya. These volumes are about 50 million times less great than the rate of methane entering the atmosphere.

arrived on the Martian equator Aug. 6, 2012, the Curiosity rover with six wheels has already established that the Red Planet was conducive to microbial life in the distant past.

AFP